The present invention relates to a dispenser member such as a pump or a valve, and to a method of installing such a dispenser member.
More particularly, such a dispenser member comprises a body in which a piston is mounted to slide so as to cause the volume of a pump or valve chamber to vary. In general, in order to move the piston, a pusher is provided that is connected to the piston via an actuator rod. Furthermore, it is known that a ferrule can be used that is engaged (preferably by force) in the body. The ferrule serves as a leaktight stopper at the top end of the body, and it defines a high abutment for the piston in the rest position in which the chamber reaches its maximum volume. The piston is urged against the ferrule by a return spring. That design is quite conventional for a pump or a valve.
A conventional dispenser member further comprises fixing means for fixing it onto or into the neck. In the present case, the fixing means comprise at least one peripheral projection that projects radially outwards. The projection serves to come into engagement in a notch formed in the inside wall of a receptacle neck. That is a technique for snap-fastening inside the neck of a receptacle. The projection(s) may be formed on the outside wall of the body or on the outside wall of a skirt that surrounds the body in tightly-fitting and preferably leaktight manner.
In order to reach a final snap-fastening position in the notch in the neck, the projection(s) must be capable of being elastically displaced radially inwards to pass through the smaller-diameter inlet section of the neck that is situated immediately above the notch.
Such a dispenser member is described in Document FR 2 792 295.
A requirement also exists that is related to the design of modern pumps or valves. It is preferable for the pump or valve to have as small a height as possible above the neck of the receptacle, which requires the body of the dispenser member to be engaged as far as possible into the neck of the receptacle. It is thus advantageous to engage the body in the neck so that its top end is situated approximately level with the top end of the neck. In which case, the ferrule engaged by force in the body is also engaged inside the neck and can extend to the level of the projection(s) formed by the fixing means. Since the ferrule is a part that is relatively rigid because it must be capable of withstanding the stress from the piston in the rest position, it is almost non-deformable, and it can therefore hinder the operation of fixing the pump inside the neck. In the above-mentioned document, provision is made for the ferrule to be put in place finally only once the projections are engaged in the notch in the neck.
An object of the present invention is to remedy the above-mentioned drawbacks of the prior art by defining a dispenser member having a ferrule which, while performing its usual function of leaktight stopper and of high abutment for the piston, also makes it easy for the dispenser member to be fixed in the neck of a receptacle provided with a snap-fastening notch.
The above-mentioned problems are solved by a dispenser member such as a pump or a valve, comprising: a body in which a piston is slidably received and in which a ferrule is engaged; and fixing means comprising at least one peripheral projection that projects radially outwards, said projection serving to come into engagement in a notch formed in an inside wall of the neck of a receptacle, said projection being elastically displaceable radially inwards so as to come into engagement in the notch in the neck by elastically deforming the body radially inwards in a deformation zone, the ferrule not being in contact with the body in said deformation zone. This means that the ferrule does not extend to the level of the deformation zone or that the ferrule is not in contact with the body at said deformation zone.
Preferably, the ferrule extends axially in the body to the level of projection, an intermediate space then being provided between the body and the ferrule to enable the body to deform radially inwards. This is particularly advantageous because it is thus possible to satisfy the above-mentioned requirement related to keeping the height of the pump above the neck as small as possible.
Thus, the projections and the body are free to deform elastically inwards into the intermediate space without being hindered by the rigid ferrule. The ferrule nevertheless retains all of its initial functions, namely those of stopper and of rest high abutment for the piston.
Advantageously, said intermediate space is formed by an inwardly-extending shoulder on the ferrule. In a variant, or in addition, said intermediate space is formed by a reduction in the thickness of the wall of the ferrule.
In a practical embodiment, the ferrule comprises a first section in tightly-fitting contact in the body and a second section spaced apart from the body at least in part to form the intermediate space. The first section is situated immediately at the inlet of the body above the projection, while the smaller second section is situated at the level of the projections.
According to another characteristic, the ferrule is provided with an abutment flange in abutment against an end of the body.
According to another feature of the invention, the fixing means are provided with a skirt which extends around the body, the projection being formed on an outside wall of the skirt, a delivery channel being formed between the skirt and the body to enable the fluid to be delivered from the body under the action of the piston. Advantageously, the body is engaged in the skirt with tight-fitting and leaktight contact so that they isolate the delivery channel between them.
In a variant, the projection is formed by an outside wall of the body.
The present invention also provides a method of fixing a dispenser member such as a pump or a valve, said dispenser member comprising: a body in which a piston is slidably received and in which a ferrule is engaged; and fixing means in which the body is received, said fixing means comprising at least one peripheral projection that projects radially outwards, said projection serving to come into engagement in a notch formed in an inside wall of the neck of a receptacle, said projection being elastically displaceable radially inwards so as to come into engagement in the notch in the neck by elastically deforming the body radially inwards; said method comprising the step of exerting sufficient pressure on the fixing means to bring the projections into the notch in the neck.
Advantageously, the ferrule is not in contact with the deformation zone of the body. Preferably, the ferrule extends axially in the body to the level of the projection, an intermediate space being provided between the body and the ferrule to enable the body to deform radially inwards.